Abstract: A crankshaft is cast in a mold to define a plurality of pin bearing journals and a plurality of main bearing journals, at least one of each has a hollow section extending therethrough. A single core is positioned within the mold to form all of the hollow sections. The single core may include a cross-section defining an elliptical shape to form hollow sections having an elliptical cross-sectional shape to further reduce the weight of the crankshaft. The hollow sections are each positioned along a path that minimizes stress within the crankshaft. The path may include a non-linear path relative to a longitudinal axis of the crankshaft or a linear path angled relative to the longitudinal axis to bend or direct the hollow sections away from high stress regions of the crankshaft. The non-circular cross section of the core may spiral about its own axis to maximize mass reduction.

Abstract: A crankshaft is cast in a mold to define a plurality of pin bearing journals and a plurality of main bearing journals, at least one of each has a hollow section extending therethrough. A single core is positioned within the mold to form all of the hollow sections. The single core may include a cross-section defining an elliptical shape to form hollow sections having an elliptical cross-sectional shape to further reduce the weight of the crankshaft. The hollow sections are each positioned along a path that minimizes stress within the crankshaft. The path may include a non-linear path relative to a longitudinal axis of the crankshaft or a linear path angled relative to the longitudinal axis to bend or direct the hollow sections away from high stress regions of the crankshaft. The non-circular cross section of the core may spiral about its own axis to maximize mass reduction.